Brownmillerite oxides for oxygen evolution catalyst

Patent metadata

Field	Value
Publication number	US-10927465-B2
Application number	US-201715444732-A
Country	US
Kind code	B2
Filing date	Feb 28, 2017
Priority date	Nov 21, 2016
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

An oxygen evolution catalyst of the formula: Sr2MCoO5 where M=Al, Ga wherein M is bonded with four oxygen atoms to form a tetrahedron. The catalyst is operated at a potential of less than 1.58 volts vs. RHE at a current density of 50 μA/cm2 for a pH of 7-13. The catalyst is operated at a potential of less than 1.55 volts vs. RHE at a current density of 50 μA/cm2 and a pH of 13. The oxygen evolution catalyst of the formula: Sr2GaCoO5 wherein the catalyst is operated at a potential of less than 1.53 volts vs. RHE at a current density of 50 μA/cm2 and a pH of 7. The oxygen evolution catalyst of formula: Sr2GaCoO5 wherein the catalyst maintains a current within 94% after 300 minutes at a potential of 1.645 volts vs. RHE wherein the current is greater than 1 milliamp and a pH of 7.

First claim

What is claimed is:

1. An oxygen evolution catalyst comprising a material of the formula: Sr2MCoO5 where M=Al, Ga wherein M is bonded with four oxygen atoms to form a tetrahedron and including conductive particles and a binder combined with particles of formula: Sr2MCoO5 where M=Al, Ga.

2. The oxygen evolution catalyst of claim 1 wherein the catalyst is operated at a potential of less than 1.58 volts vs. RHE at a current density of 50 μA/cm2 and a pH of from 7 to 13.

3. The oxygen evolution catalyst of claim 1 wherein the catalyst is operated at a potential of less than 1.55 volts vs. RHE at a current density of 50 μA/cm2 and a pH of 13.

4. The oxygen evolution catalyst of claim 1 wherein the material maintains a current within 97% after 300 minutes at potentials of from 1.51 to 1.55 volts vs. RHE.

5. The oxygen evolution catalyst of claim 1 wherein the material has the formula Sr2AlCoO5 and is operated at a potential of less than 1.55 volts vs. RHE at a current density of 50 μA/cm2 and a pH of 13.

6. The oxygen evolution catalyst of claim 5 wherein the material maintains a current within 97% after 300 minutes at a potential of 1.55 volts vs. RHE.

7. The oxygen evolution catalyst of claim 5 wherein the material has a Tafel slope of 89 mV per decade.

8. The oxygen evolution catalyst of claim 1 wherein the material has the formula Sr2GaCoO5 and is operated at a potential of less than 1.51 volts vs. RHE at a current density of 50 μA/cm2 and a pH of 13.

9. The oxygen evolution catalyst of claim 8 wherein the material maintains a current within 97% after 300 minutes at a potential of 1.51 volts vs. RHE.

10. The oxygen evolution catalyst of claim 8 wherein the material has a Tafel slope of 51 mV per decade.

11. The oxygen evolution catalyst of claim 1 including An a material of the formula: Sr2GaCoO5 wherein the catalyst is operated at a potential of less than 1.53 volts vs. RHE at a current density of 50 μA/cm2 and a pH of 7.

12. The oxygen evolution catalyst of claim 11 wherein the material maintains a current within 96% after 300 minutes at a potential of 1.530 volts vs. RHE.

13. The oxygen evolution catalyst of claim 11 wherein the material maintains a current within 96% after 300 minutes at a potential of 1.593 volts vs. RHE.

14. The oxygen evolution catalyst of claim 11 wherein the material maintains a current within 94% after 300 minutes at a potential of 1.645 volts vs. RHE.

15. The oxygen evolution catalyst of claim 14 wherein the current is greater than 1 milliamp.

16. The oxygen evolution catalyst of claim 11 wherein the material has a Tafel slope of 87 mV per decade.

17. The oxygen evolution catalyst of claim 1 wherein the catalyst is operated at a potential of less than 1.58 volts vs. RHE at a current density of 50 μA/cm2 and a pH of 7.

18. An oxygen evolution catalyst comprising a material of the formula: Sr2GaCoO5 wherein the catalyst maintains a current within 94% after 300 minutes at a potential of 1.645 volts vs. RHE wherein the current is greater than 1 milliamp and a pH of 7.

Assignees

• Toyota Eng & Mfg North America

Inventors

• Zhou Li Qin
• Gunugunuri Krishna Reddy
• Ling Chen
• Jia Hongfei

Classifications

• C25B11/077 Primary

  the compound being a non-noble metal oxide · CPC title

• C01P2002/72

  by d-values or two theta-values, e.g. as X-ray diagram · CPC title

• C25B11/051

  Electrodes formed of electrocatalysts on a substrate or carrier · CPC title

• C01P2006/40

  Electric properties · CPC title

• Y02E60/36

  Hydrogen production from non-carbon containing sources, e.g. by water electrolysis · CPC title